Process for producing muconic acid and its derivatives



Patented Dec. 19,1950

UNITED STATES PATENT ()FFICE Anton Wacek, Gra'z, Austria, assignor to Harald Frederiksen, New York, N. Y.

No Drawing. Application December 9, 1948, Serial No. 64,430

14 Claims.

The present invention relates to the production of muconic acid (2,4 hexadienedioic acid HOOCCH:CHCH:CHOOI-I) and its derivatives. It is'well known in the art to obtain muconic acid and its derivatives from various phenols by breaking up the benzene nucleus by oxydation, while using a solution of peracetic acid with glacial acetic acid as oxidizing agent. This reaction was particularly studied by J. Boeseken and his coworkers (see for example Koninkl. Akad. Wetensch. Amsterdam, Proceedings 34, 1292 (1931), 35, '750 (1932) and Rec. Trav. Chim. Pays-Bas 51, 964 (1932), 54, 345 (1935)). Various concentrations and amounts of peracetic acid and various temperatures were used when carrying out this reaction. The yields however obtained in this process were only mediocre varying between 20 and 36%. The oxidation recation proceeds only slowly and the final product is impure due to incomplete reaction. The yield obtained of derivatives of muconic acid by the oxidation of cresols or chloropheno s is even smaller.

An object of this invention is to increase the yield of muconic acid in the process of producing muconic acid or its derivatives from phenols. Another object is to provide conditions which allow of a more complete and more rapid reaction. A further object of the invention is to produce muconic acid in a purer state than was possible hitherto. Other objects will appear as the specification proceeds.

I have found that the reaction set forth above, consisting in breaking up the nucleus of benzene by oxidizing of phenols or their derivatives is catalytically activated by metal salts of inorganic or organic acids, so that an increased yield of muconic acid, in some cases a yield amounting to 80% or more of the theoretical yields is obtained. Especially the salts of the metals of the iron group (Fe, Ni, Co) are suitable as catalysts in this process although salts of other elements, for instance Na, Ca, Hg, Cd, Zn, Cu, Cr, Mn also lead to a remarkable improvement in the oxidation process.

I have further found that in carrying out this reaction a temperature range between C. and 15 C. is optimal and that a concentration of per acetic acid between and 30%, particularly cetween and is most suitable. Preferably an excess of 5 to of *peracetic acid over the calculated amount is used. Beside glacial acetic acid other solvents for the phenols and their deriether, chloroform and carbontetrachloride.

Examples (1) 16 to 18 parts by weight of a solution of peracetic acid in glacial acetic acid, containing 10% of peracetic acid are added to 1 part by weight of pyrocatechol [CeH4(OH) 2], while being cooled and continuously stirred. After 10 minutes, 0.02% of acetate of cobalt (calculated on the amount of pyrocatechin used), dissolved in glacial acetic acid are added. The temperature is maintained at 10 C. A precipitate of muconic acid settles out and is filtered 01f from the reaction mixture after 4 to 5 days. After standing some time more a second quantity of muconic acid is precipitated in most cases from the mother liquor. Both precipitates give a yield of to A further portion of muconic acid may be obtained from the mother liquor by evaporating the solution in vacuo, diluting the residue with a solvent (e. g. acetone, acetic ether, concentrated hydrochloric acid) and exhausting the liquid by suction. The total yield amounts to to By using acetate of nickel or of iron the same results are obtained.

(2) 16 to 18 parts of weight of a solution of .peracetic acid in glacial acetic acid, containing 10% of peracetic acid are added to 1 part by weight of pyrocatechin, while being cooled and continuously stirred 0.03% acetate of cadmium, calculated on the amount of pyrocatechol used, dissolved in glacial acetic acid are added, after 10 minutes. The temperature of the reaction mixture is maintained at 10 C. The precipitate of muconic acid settling out is filtered off after 4 to 5 days. Generally a second amount of muconic acid settles out from the mother liquor after standing for some time. The amount of both precipitates corresponds to a yield of 60 to 65%. A further amount of muconic acid may be obtained by evaporating the residual solution in vacuo, diluting the residue with a solvent such as acetone, ethylacetate, concentrated hydrochloric acid or the like, and exhausting the liquid by suction. The total yield amounts to 65 to 70%. When using acetate of manganese in the place of acetate of cadmium, the yield amounts to 50-55%, when using acetate of copper the amount yields to 60%, when using acetate of mercury the yield amounts to 55%. When using other salts the yield tends to be somewhat lower.

(3) 5 to 27 parts of weight of a solution of peracetic acid in glacial acetic acid is added to 1 part by weight of phenol (CcHsOI-I), while being stirred and cooled. After 10 minutes, 0.02% of acetate-oi cobalt (calculated on the amount of phenol used), dissolved in glacial acetic acid are added. The temperature is maintained at 10 C. The precipitate of muconic acid formed is filtered off after 4 to 5 days. The yield amounts to 33%. After distilling of the solution of peracetic acid the residue is diluted with ether and filtered. Total amount of muconic acid 45 (4) A solution of 2.5 to 3 parts of weight of perbenzoic acid dissolved in 23 parts of chloroform are added to 1 part by weight of pyrocatechol, while being cooled and continuously stirred. After minutes 0.02% of acetate of cobalt (calculated on the amount of pyrocatechol used) dissolved in a small amount of glacial acid are added. The temperature is maintained at 10 C. After 5 days the precipitate of muconic acid is filtered oiT. The yield of muconic acid thus obtained amounts to 55 to 60%. The residual solution is evaporated in vacuo; the residue consists mainly of muconic acid and benzoic acid, Whichare separated by repeated crystallisation from water. Total yield of muconic acid 63 to 70%.

(5) 12 to 15 parts by weight of a solution of performic acid in formic acid, containing 10% of performic acid, are added to 1 part by weight of pyrocatechol while being well cooled and vigorously stirred. After 10 minutes 0.01% acetate of cobalt (calculated on the amount of pyrocatechol used) dissolved in glacial acetic acid are added to the reaction mixture. The temperature is maintained at 10 C. The precipitate of muconic acid formed is filtered ofi after 5 days. The yield of muconic acid amounts to 50 to 60%. The residual solution is evaporated in vacuo, and

the residue diluted with a solvent (e. g. acetone,

acetic ether, concentrated hydrochloric acid) and sucked off. The total yield of muconic acid amounts to 60 to 70%.

(6) 19 to 23 parts of a solution of peracetic acid in glacial acetic acid, containing 10% of peracetic acid are added to 1 part by weight of p-chlorophenol. At the same time 0.03% of acetate of cobalt (calculated on the amount of chlorophenol used), dissolved in glacial acetic acid are added. The temperature of the reaction mixture is maintained at 10 C. After 10 days the precipitate of chloromuconic acid formed is filtered off. The yield of chloromuconic acid amounts to 15-20%. The residual solution is evaporated in vacuo, the residue diluted with a solvent (e. g. acetone, acetic ether) filtered off and repeatedly crystallized. The total yield of chloromuconic acid amounts to 22% in comparison with a yield of 12% when working in absence of said catalyst.

('7) 22 to 26 parts by weight of a solution of peracetic acid glacial acetic acid are added to 1 part of weight of p-cresol while cooling and continuously stirring the mixture. After 10 minutes 0.02% of acetate of cobalt (calculated on the amount of the p-cresol used), dissolved in glacial acetic acid are added to the reaction mixture. The temperature is maintained at about 10 C. After 6 days the precipitate of methylmuconic acid is filtered ed. The yield amounts to 22-25%. A further portion ofmethylmuconic acid is obtained by evaporating the mother liquor in vacuo diluting the residue with a solvent (acetone, acetic ether etc.) and sucking off. The residue is then crystallized from chloroform. Total yield 26 to 32% in comparison to 5 to 15% obtained when working under the same conditions but without the use of the catalyst.

In the following claims I use the term muconic acid in its broad sense to include besides the muconic acid itself also its derivatives and the term phenol or phenol compound to include not only the ordinary phenol or carbolic acid but also phenols containing more than one hydroxyl group and the derivatives of monhydric phenol, for instance chlorophenol or cresol as well as the derivatives of dior polyhydric phenols.

What I claim is:

1. A process for producing a compound selected from the group consisting of muconic acid and its derivatives, said process comprising the steps of dissolving a phenol compound in a solution of a peracid dissolved in a solvent for the phenol to be treated, and adding a metal salt acting as a catalyst to the phenol solution thus obtained.

2. A process for producing muconic acid, comprising a first step of treating a phenol with a solution of a peracid dissolved in a solvent for the phenol to be treated, and a subsequent step of treating said phenol with said peracid in the presence of a metal salt acting as a catalyst.

3. A process for producing muconic acid, comprising a first step of treating a phenol with a solution of a peracid dissolved in a solvent for the phenol to be treated, and a subsequent step of treating said phenol with said peracid in the presence of a metal salt acting as a catalyst, the metal of said salt being an element of the iron group.

4. A process for producing muconic acid, comprising a first step of treating a phenol with perac'etic acid dissolved in glacial acetic acid, and a subsequent step of treating said phenol with said peracetic acid in the presence of a metal salt acting as a catalyst.

5. A process for producing muconic acid, comprising a first step of treating a phenol with perbenzoic acid dissolved in chloroform, and a subsequent step of treating said phenol with said perbenzoic acid in the presence of a metal salt acting as a catalyst.

6. A process for producing muconic acid, comprising a first step of treating a phenol with performic acid dissolved in formic acid, and a subsequent step of treating said phenol with said performic acid in the presence of a metal salt acting as a catalyst.

'7. A process for producing muconic acid, comprising a first step of trea ing a phenol with a peracid dissolved in a solvent for the phenol, a subsequent step of treating said phenol at a temperature between 0 C. and 15 C. for a protracted period of time with said peracid in the presence of a metal salt acting as a catalyst, filtering off the precipitates, formed, evaporating the mother liquor in vacuo, diluting the residue with a solvent for the phenol treated, sucking oil the solvent and recovering the residue.

8. A process for producing muconic acid, comprising a first step of treating Dyrocatechol with a peracid of the group consisting of peracetic acid, performic acid and perbenzoic acid, dissolved in a solvent for pyrocatechol, a subsequent step of treating said pyrocatechol with said peracid in the presence of a metal salt acting as a catalyst at a temperature of about 10 C. for a protracted period of time, filtering off the precipitates formed, evaporating the mother liquor in vacuo, diluting the residue with a solvent for the pyrocatechol treated, sucking oil the solvent and recovering the residue.

9. A process for producing muconic acid, comprising a first step of treating a phenol with a peracid dissolved in a solvent for the phenol treated, a subsequent step of treating said phenol with said peracid in the presence of a metal salt of acetic acid at a temperature between C. and 15 C. for a protracted period of time, filtering oil the precipitates formed, evaporating the mother liquor in vacuo, diluting the residue with a solvent for the phenol treated, sucking oil the solvent and recovering the residue.

10. A process as claimed in claim 9, in which the metal salt of acetic acid is cobalt acetate.

11. A process as claimed in claim 9, in which the metal salt of acetic acid is nickel acetate.

12. A process as claimed in claim 9, in which the metal salt of acetic acid is iron acetate.

13. A process for producing muconic acid, comprising a first step of treating a phenol with peracetic acid dissolved in glacial acetic acid, said solution containing to 30% of peracetic acid and being used in an amount corresponding to an excess of about 5 to 25% of the theoretically required amount of peracetic acid, a subsequent step of treating said phenol with said peracetic acid in the presence of a metal salt acting as a catalyst, for a protracted period of time at a temperature between 0 C and 15 C., and recovering the muconic acid formed.

14. A process for producing muconic acid, comprising a first step of treating a phenol with peracetic acid dissolved in glacial acetic acid, said solution containing 10 to 15% of peracetic acid and being used in an amount corresponding to an excess of about 5 to 25% of the theoretically required amount of peracetic acid, a subsequent step of treating said phenol with said peracetic acid in the presence of a catalytically acting metal acetate, maintaining said reaction mixture at a temperature of about 10 C. for a protracted period of time and recovering the muconic acid formed.

ANTON WACEK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,265,948 Loder Dec. 9, 1941 FOREIGN PATENTS Number Country Date 508,526 Great Britain July 3, 1939 OTHER REFERENCES Boeseken et a1., Rec. trav. chim. Pays-Bas, vol. 54, pp. 345-352 (1935). 

1. A PROCESS FOR PRODUCING A COMPOUND SELECTED FROM THE GROUP CONSISTIN GOF MUCONIC ACID AND ITS DERIVATIVES, SAID PROCESS COMPRISING THE STEPS OF DISSOLVING A PHENOL COMPOUND IN A SOLUTION OF A PERACID DISSOLVED IN A SOLVENT FOR THE PHENOL TO BE TREATED, AND ADDING A METAL SALT ACTING AS A CATALYST TO THE PHENOL SOLUTION THUS OBTAINED. 